1. Technical Field
The present invention relates to a vehicle safety apparatus and, in particular, to an apparatus for inflating an inflatable vehicle occupant protection device, such as an air bag.
2. Description of the Prior Art
It is known to inflate a vehicle occupant protection device, such as an air bag, to help protect a vehicle occupant. The air bag is inflated by inflation fluid from an inflator. The air bag is inflated into a position between the vehicle occupant and a portion of the vehicle to help protect the vehicle occupant in the event of a vehicle collision or of a rollover condition of the vehicle.
One type of air bag, known as a side curtain, is inflated between the vehicle occupant and the side structure of the vehicle. It is desirable to maintain a side curtain inflated for a period of seven to ten seconds in order to help protect the vehicle occupant in the event of a rollover condition of the vehicle.
The present invention is an apparatus for inflating an inflatable vehicle occupant protection device. The apparatus comprises a container and a refrigerant under pressure in the container in a liquid state. The container is openable to enable the refrigerant to flow out of the container into the inflatable device. At least a portion of the refrigerant that flows from the container vaporizes to a gaseous state to help inflate the inflatable device. The apparatus includes an aspiration passage enabling aspiration of ambient air into the inflatable device with the refrigerant to help inflate the inflatable device. At least a portion of the refrigerant that flows from the container is located in the inflatable device in a liquid state, That portion of the refrigerant thereafter changes from the liquid state to the gaseous state while in the inflatable device to help maintain the inflatable device in the inflated condition.